Lec 29 Motor System Clinical Correlations Flashcards
Do you get spasticity in UMN or LMN lesion?
UMN
What is typicall distribution of weakness in upper motor neuron lesion?
in upper extremities: flexors stronger than extensors
in lower extremities: extensors are stronger than flexors
look at shoes: adductors stronger than abductors –> outside may be more worn
Do you see babinski [big doe upgoing] in UMN or LMN lesion?
in UMN lesions
What are some examples of UMN lesions?
cerebrovascular accident [stroke], intracranial tumor, cervical spine injury
What are some examples of LMN lesions?
motor neuron disease, peripheral nerve neuropathy, polio, spinal cord injury resulting in nerve root compression
What is normal reflex on the scale?
2+ is normal
What is normal muscle strength on the scale?
5
3 = against gravity
What is hemiplegic gait?
- arm in flexion with weakness of extensors of fingers/wrist
- hand and fingers tightly clenched
- outward swing of leg
- reduced arm swing
what is spastic gait?
- both legs stick, have toe walking
- walking slow and stiff
- bilateral
- hyperreflexia
what is frontal [magnetic] gait?
- difficulty getting out of chair and finding center of gravity
- small steps as if feet stuck to ground
What disease is frontal [magnetic] gait associated with?
seen in normal pressure hydrocephalus –> on exam usually cognitive impairment
What is amyotrophic lateral sclerosis?
combined anterior horn + pyramidal tract disease = UMN and LMN
- no sensory, cognitive, or oculomotor deficits
characterized by: rapid progressive weakness, muscle atrophy and fasciculations, muscle spasticity, difficulty speaking, difficulty swallowing, difficulty breathing
Causes of ALS?
can be due to defect in superoxide dismutase 1
What are 2 viruses that can affect anterior horn?
- polio
- west nile
What is treatment for ALS?
riluzole [prolongs survival 2-3 mo]
prognosis = 3-5 years
What are other disease that might present like ALS? how do you determine ALS?
- determine ALS by demonstrating disease above foramen magnum [ex. dysarthria, swallowing disorder, jaw jerk]
otherwise could be: tumor of brainstem or cervical spondylosis
What is primary lateral sclerosis?
- UMN, no LMN involvement
- lesion of motor cortex
- slowly progressive spastic quadriparesis
what is progressive spinal muscular atrophy?
- LMN, no UMN involvement
- weakness, wasting, fasciculations with variable age onset
What is cervical spondylosis?
can be UMN and LMN involvement
but no involvement above foramen magnum
What presentation in a lesion of motor cortex?
- UMN disease
ex. primary lateral sclerosis
what presentation in a lesion of internal capsule?
- contralateral motor or sensory deficit
What presentation in a lesion of brainstem?
- ipsilateral cranial nerve deficits + contralateral motor deficits
- jaw jerk reflex impaired
what presentation in an anterior horn spinal cord injury?
- LMN disease = ipsilateral weakness, atrophy, fasciculations, hyporeflexia
- absence of cognitive or sensory changes
ex. spinal muscular atrophy, polio, west nile
what presentation in peripheral neuropathy?
- distal weakness [longest nerves first]
- steppage gate [LMN leg weakness]
- foot drop
- weakness/hyporeflexia
What is guillain barre?
type of peripheral neuropathy
get ascending paralysis
associated with campylobacter infection
What presentation in NMJ disorder?
- fluctuating wekness, fatigable muscles
dysarthria, dysphagia, diplopia, ptosis
What is myasthenia gravia?
type of NMJ disorder
- autoantibodies against ACh receptor
- muscle weakness, ptosis, gets worse with use
What presentation in myotonia?
disorder of muscle membrane
- slow relaxation of muscle after voluntary contraction
- improves when muscle warmed
what presentation in myopathy?
- proximal weakness
- normal sensation, normal sphincter, preservation deep tendon reflex
- gowers sign
what is gower’s sign?
arms/hands used to get body out of seated position
sign of muscle myopathy
What does steppage gate suggest?
LMN leg weakness
What is acute inflammatory demyelinating polyradiculopathy?
- most common variatn of guillain barre
- autoimmune disorder destroys schwann cells
- get inflammation and demyelination of peripheral nerves and motor fibers
What are sigsn of acute inflammatory demyelinating polyradiculopathy?
- symmetric ascending muscle weakness/paralysis beginning in lower extremities
- facial paralysis in 1/2 pts
- high CSF protein
- papilledema
How do you treat myasthenia gravis?
ACHesterase inhibitors
What is botulism?
- toxin produced by clostridium botulinum prevents ACh release
- paralysis of face, spreads to limbs, ptosis
in kids = floppy baby
What is tick paralysis?
due to neruotoxin in tick’s salivary gland
- weakness in both legs –> ascending paralysis
- looks like guillan barre
What is ciguatera toxin?
- get ir from ingesting certain fish
- after ingestion –> pts get N/V, weakness, muscular cramps, metallic taste, paralysis, coma, resp failure
